SOLUTION: Neil can paint a 3 by 3 meter room in 6 3/4 hours,whereas Den can do the job in 4 1/2 hours. If they are both hired to do job, then how many hours will it take for them to finish p

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Question 1067097: Neil can paint a 3 by 3 meter room in 6 3/4 hours,whereas Den can do the job in 4 1/2 hours. If they are both hired to do job, then how many hours will it take for them to finish painting the room?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Add their rates of painting to get their
rate painting together
Call the room to be painted [ 1 job ]
---------------------------------
Neil's rate:
[ 1 job ] / [ 6.75 hrs ]
Den's rate:
[ 1 job ] / [ 4.5 hrs ]
Let their rate painting together =
[ 1 job ] / [ t hrs ]
-------------------------------
+1%2F6.75+%2B+1%2F4.5+=+1%2Ft+
Multiply both sides by +6.75%2A4.5%2At+
+4.5t+%2B+6.75t+=+6.75%2A4.5+
+4.5t+%2B+6.75t+=+30.375+
+11.25t+=+30.375+
+t+=+2.7+
Painting together, it will take them 2.7 hrs